The Mouse Core is formulated to provide specialized mice to the investigators of this program. The Mouse Core will provide: 1) transgenic mice; or 2) NOD/SCID mice for human-mouse xenografts. The Core utilizes equipment and expertise already in place in the Hermen B Wells Center for Pediatric Research, including two microinjection microscopes, 8 rodent rooms, a Cesium irradiator and specialized HEPA-filtered air mouse cage racks which house the NOD/SCID mice. The core will receive DNA plasmids from investigators and will derive pups from up to 5 injection sessions/construct. Tall DNA will be provided to the investigators for confirmation of transgene presence. The Mouse Core will maintain adequate numbers of breeding mice for each transgene to provide investigators experimental mice in a timely fashion. The NOD/SCID facility is maintained with entry restrictions. The Mouse Core will provide both housing and experimental manipulation serve for each investigator to minimize the risk of colony contamination. All animals in this core are housed under the supervision of the Laboratory Animal Resource Center, an AAALAC-approved facility.